Combined controlled transmission and carburetor



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V. A. GOETZ COMBINED CONTROLLED TRANSMISSION AND CARBURETOR Filed DecVZIS. 1954 i 1 IGMI-T oN gnaw an INVENTOR.

COMBINED CONTROLLED TRANSMISSION p a AND CARBURETOR Vincent Goetz, Detroit, Mich., assignor to Holley Carburetor Company, Detroit, Mich., a corporation of Michigan Application December 23,1954, Serial No. 477,198

claims. (01. 74-472 The present invention relates to a carburetor and more particularly, to a carburetor including means for controlling the air pressure within the bowl or fuel. chamber above the level of fuel therein.

i Tests with motor vehicles having overdrive have established that it ispossible to operate the vehicle with a considerably leaner fuel mixture supplied to the internal combustion engine .while driving in overdrive as compared to conventional drive. The same considerations apply to operation at diiferent axle ratios. The present invention has been designed to provide means for changing the pressure or the average pressure within the float chamber of a carburetor in accordance with whether the vehicle is driving in overdrive or conventional drive.

It is an object. of the present invention to provide a carburetor having means for controlling the pressure within the fuel chamber. a

a It is a further object of the present inventionto provide a carburetor having a fuel chamber and a barrel including a Venturi, a firstpassage connecting the interior of the fuel, chamber tothe barrel in advance of the Venturi, a second passage connectinguthe interior of the.

float chamber with atmosphere, and valve means for controlling said passages.

More specifically, it is an object of the present invention to provide a carburetor having a barrel provided with a Venturi and a float chamber, a, tube extending from the upper portion of the float chamber to the barrel in advance of the Venturi, a port connecting the upper portion of the chamber to atmosphere, and a valve controlling said port.

' It is a further object of the present invention to provide a motor vehicle having selectively operable overdrive, an internal combustion engine including a carburetor having a fuel chamber, and means responsive to selection of overdrive for controlling air pressure within the fuel chamber.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a more or less diagrammatic sectional view of a carburetor embodying the present invention.

Figure 2 is a diagrammatic view showing the atmospheric vent controlled in conjunction with the overdrive.

Figure 3 is a diagrammatic view illustrating the atmospheric vent controlled by the ignition switch.

The carburetor comprises a casing indicated generally at '10 illustrated as assembled from a plurality of components adapted to be mounted on an internal combustion engine 11, said casing providing an internal barrel 12 shaped to provide a restricted portion forming a Venturi 14. The casing includes a bowl providing a float controlled fuel chamber 16, a float controlling admission of fuel to the chamber being illustrated at 18 and operating to control a fuel inlet valve 20.

The carburetor illustrated is a simple down draft carburetor and flow of air through the barrel induced by 2,995,013 Patented Sept. 22, 1959 ice operation of the engine causes a reduction of pressure in thethroat of the Venturi as is well understood and operates to draw fuel from the chamber through the main metering jet 22 into the main well 24 whence it is drawn upwardly and thence downwardly through a passage 26, whence it is dischargedthrough the main discharge nozzle 28. A second passage 30 connects the well 24 to the idle discharge port 32 and idle transfer 'holes 34. The operation is controlled by the throttle valve 36 and the choke 35; t

Intheoperation the rate of flow of fuel through the main discharge nozzle 28 is of course dependent upon the difierence in pressure existing within the fuel chamber 16 and the outlet of the main discharge nozzle within the throat of the Venturi. The actual pressure existing within the throat of the Venturi depends upon a'number of factors, such for example asthe'opening of the throttle valve 36, the load on the engine, etc. However, for any given condition it will be evident that the rate'of flow of fuel is dependent upon pressure existing within thev fuel chamber 16.

. In orderto provide means. for selectively controlling thepressure existing within the fuel chamber above the level of the fuel therein the chamber is provided with an upward extension 37 which in turn is provided with an atmosphere port 38. In order to control this port a small housing 40' having a plurality of ports 42 is attached to the casing over and surrounding the atmosphere port 38. Located within the housing 40 is a solenoid including windings 44 and an armature 46. The armature 46 at its inner end includes a ring 48 adapted to seat on a valve seat 50 and thus to control admission of atmospheric air to the interior of the fuel chamber 16.

The upward extension 37 of the fuel chamber 16 is provided with a second port 52 opening into the interior of the barrel 12. Received within the port 52 is an up: wardly extending tube 54 which connects the interior of the fuel chamber with the barrel at a point in advance or ahead of the throat of the Venturi 14.

l During operation of the engine a flow of air induced through the barrel by engine operation resultsin a pressure existing at the open end of the tube 54 which is somewhat below atmospheric but substantially above the reduced pressure existing within the throat of the Venturi. The reduction in pressure at the entrance to the tube 54 is of course due to resistance to flow of air through the barrel and where air cleaners are provided, such as indicated at 55,1as is conventional, this resistance to flow is increased and the reduction in pressure is enhanced.

With the parts in the position illustrated. in Figure 1,

the interior of the float controlled fuel chamber is in communication with atmosphere and accordingly, the flow of fuel through the main discharge nozzle 28 is dependent upon the diiference in pressure between the instantaneous pressure Within the throat of the Venturi and atmospheric pressure. If now, the valve formed by the ring 48 is closed, the interior of the float chamber is disconnected from atmospheric pressure and is then connected through the tube 54 to the interior of the barrel so that a pressure value intermediate atmospheric pressure and the instantaneous pressure within the throat of the Venturi is maintained. This will have the immediate result of reducing the quantity of fuel discharged from the main discharge nozzle 28 so that a leaner mixture is supplied to the internal combustion engine.

The windings 44 of the solenoid are connected through an electrical conductor indicated at 56 to an electrical circuit actuated by an overdrive selector indicated diagrammatically at 57. The arrangement is diagrammatically illustrated in Figure 2 where the engine is illustrated at 60, the transmission at 62, and the overdrive at 64. The overdrive selector 57 not only controlsthe overdrive but simultaneously actuatcs the atmospheric vent contained within the housing 40. Thus, the valve willcause'the carburetor to'mete'r' as a balanced carbu While" driving but allow it to met'er as an atmospheric retor by venting through the tube 54 only, in overdrive,- vented carburetor whiledriving: in the conventional drive; Inasmuch as the solenoid is connected so as to close the atmospheric valvewhen in overdrive; the valve" will keep the atmospheric vent or port 33 open While the engine is shutoff, therebypreventing hot starting trouble dueto percolation.

Preferably, the solenoid valve is connected into the" electrical connection of the overdrive electrical circuit. As" is convention in overdrive transmissions, when the ear reaches a: predetermined speed the overdrive governor completesa* circuit; thus shifting into overdrive, and completionof this circuit is employed to energize the windings" 44 ofthe solenoid herein; This Willclose the valve provided by the ring 48, thereby closing theatrnospheric carburetor bowl vent- 38 and causing the carburetor to meter a leaner mixture" to the main discharge nozzle When the overdrive electrical circuit is broken by the overdrive governor at a speed somewhat less than that sufiicient to energize the circuit, the solenoid winding 44 is de-energized and the carburetor bowl vent 38: is opened,- allowing the carburetor to meter a richer mixture as required for satisfactory whiledriving in the conventional axle ratio.-

This device could alsobe used to control an auxiliary fuelvalve,-or aii b'leedg-in order to obtainthe proper fuelai rmixture: differential for the different axle ratios.

The invention is also useful as an anti-percolation" valve on any installation whichrequires a fully balanced carburetor. By connecting the solenoid windings 44' to the O'n side of the ignition switch, the carburetoratmospheric bowl vent 38 will be closedwhile the engine is in operation, but -w-ill be open when the engine is shutoif.

This arrangement isdiagrammatically illustrated in- Figure 3 Where the ignition switchis illustrated at 66 and the housing 46 containing the solenoid windings 44' is shown. The ignition circuit, a portion ofwhich is indicated at 68; isconnected to the solenoid by conductor 70.

The drawings and the foregoing specification constitute a description of the improved carburetor in such full, clearg concise andexact terms as to enable any per son skilled in the art topractice the invention, the scopeof which is indicated by the appended claims.

What I claim as my invent-ion is:

1 In an automobile having a transmission including overdrive, an internal combustion engine, and a carburetor for supplying a combustible mixture offuel and air thereto, said carburetor having a barrel including a Venoperation turiin whichsub-atmospheric pressure exists during oper-- ation of the engine, a fuel chamber, and a fuel passage connecting said fuel chamber to said Venturi through which fuel is drawn at a rate dependent on the difference in pressure between said chamber and said Venturi, transmission control means for connecting and disconnecting said overdrive, and carburetor control means-responsive to said transmission control means: for varying the difference in pressure between said Venturi and chamber,

said carburetor control 'means:including= meansfor selectively connecting the interior'of the chamber to'different sources of pressure.

2. Apparatus as defined in: claim. 1 in which one of said sources of pressure is atmosphere.

3. Apparatus asdefined in claim 2 in which the other source of pressure is the barrel of the carburetor in advance of said Venturi.

42 an automobile having a transmission including overdrive, an internal combustionengine, and a carbureto'r for" supplying a combustible mixture offuel' and air thereto, said carburetor having a barrel including a Ven turi in-which sub atmospheric pressure exist-s during operationof the engine, a fuel' chamber,-and a fuel passageconnecting said fuel. chamber to said- Venturi through which fuel isi drawn at a rate dependent on=the diiierencein pressure between said-chamber and said- Venturi, transmission: control means for connecting and disconnecting said: overdrive, andcarburetor control means responsive tosaid: transmission controlmeansfor varying the differ ence in pressure betweerr said Ventu'ri and chamber, said carburetor control: means comprising a first passage con-- nesting: said chamber to: atmosphere; a second passage connecting said chamber to the barrel of said carburetor at a point in advance of said Venturi, and a two-posi-- tion v-alve' movable topermit air flow through one or both of said first and second passages.

5. Apparatus as" defined in claim 4 comprising. a' soleneid' operable by said transmission control means connected to said valve 

